Missouri Phone Number Guide

Quick Reference

• Country: United States (Missouri)
• Country Code: +1
• International Prefix: 011 (for calls from the U.S.)
• National Prefix: 1 (for long-distance calls within the U.S.)

Overview

Discover the intricacies of Missouri's phone number formats, dialing procedures, and telecommunications regulations. This guide is tailored for telecom professionals, developers, and systems administrators seeking precise and current information.

Number Formats

General Number Structure

Missouri adheres to the North American Numbering Plan (NANP), structuring phone numbers as follows:

• Country Code: +1
• Area Code: 3 digits
• Subscriber Number: 7 digits (XXX-XXXX)

Example Number Format

+1 (Area Code) XXX-XXXX

Area Codes in Missouri

Missouri is segmented into several area codes, each serving distinct geographic regions:

Toll-Free Numbers

Toll-free numbers in Missouri follow the national format:

• Format: 800/888/877/866/855/844/833 + 7 digits
• Example: +1 800 555-1234

Emergency Numbers

• 988: National Suicide Prevention Lifeline
• 911: Emergency services

Numbering Scheme and Regular Expressions

The structure of Missouri phone numbers can be represented using regular expressions:

General Number (NANP)

^\+1\s?(\d{3})\s?(\d{3})\s?(\d{4})$

Toll-Free Number

^\+1\s?(800|888|877|866|855|844|833)\s?(\d{3})\s?(\d{4})$

Example Validation Function (JavaScript)

function validateMissouriPhoneNumber(number) {
    const generalNumberPattern = /^\+1\s?(\d{3})\s?(\d{3})\s?(\d{4})$/;
    const tollFreePattern = /^\+1\s?(800|888|877|866|855|844|833)\s?(\d{3})\s?(\d{4})$/;
    return generalNumberPattern.test(number) || tollFreePattern.test(number);
}

Dialing Procedures

Domestic Calls

• Local Calls: Dial the 10-digit number (area code + 7-digit subscriber number).
• Long-Distance Calls: Dial 1 + 10-digit number (1 + area code + subscriber number).

International Calls

• Outgoing from Missouri: Dial 011 + country code + area code + subscriber number.
• Incoming to Missouri: Dial your international access code, followed by +1, the area code, and the subscriber number.

Recent or Upcoming Changes

Area Code Overlay

• 573 Region: A new area code, 235, will be introduced as an overlay in the 573 region, effective March 24, 2024.
• 816 Region: The 975 area code overlay was introduced on October 13, 2023.
• 314 Region: The 557 area code overlay was introduced on August 12, 2022.

Number Portability

Missouri supports number portability, allowing users to retain their phone numbers when switching providers, as mandated by the Federal Communications Commission (FCC).

Major Telecom Operators

The leading telecom operators in Missouri include:

• AT&T
• Verizon Wireless
• T-Mobile
• Sprint (now part of T-Mobile)
• CenturyLink

These operators manage various number ranges, although specific details on number ranges are not publicly disclosed.

Regulatory Body

The Missouri Public Service Commission (PSC) regulates telecommunications in Missouri. Visit their official website for the most accurate and up-to-date information.

ITU-T Recommendations

Missouri adheres to ITU-T E.164 recommendations, standardizing international public telecommunication numbering plans.

Number Allocation and Management

Number allocation and management in Missouri are governed by the North American Numbering Plan Administration (NANPA) under the oversight of the FCC. The Missouri PSC also plays a role in managing local number resources.

Technical Restrictions

Golden Numbers

There are no specific regulations or restrictions regarding golden numbers in Missouri.

Number Blocking

Number blocking is generally handled by individual carriers, with no specific state-level restrictions.

Technical Considerations

For Developers and Systems Administrators

• Validation: Ensure phone numbers conform to the NANP format using regular expressions.
• Number Portability: Implement systems that support number portability as per FCC regulations.
• Area Code Updates: Stay updated on new area code overlays, as these changes may affect dialing procedures and validation logic.

For the most up-to-date information on telecommunications regulations in Missouri, please consult the official website of the Missouri Public Service Commission.